Fan belt



B. H. PRATT FAN BELT Filed-Apri; 1a, 1924 .BENJJMAN H. PPM

/NvsN-rQR ATTORNEY Y Patented 25., 1,925. Y*

' .UNITED STATES PATENT orifice.

. A BENJAMIN Tsi/PRATT, or MTLWAUKEE, WISCONSIN, AssToNon 'ro 'rein Frsx :RUBBER `COMPANY, OF CIHICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF MTA-SSACHU-Iv SETTS.

FAN BELT."

Appuauon and April 1s, 1924. semi Nn. 707,399.

To aZZ who/nf t may coment;

Be it known that I, BENJAMIN H. PRATT a citizen of the United States, and a resident of Milwaukee in the county of Milwaukee and 'State'of Wisconsin, havev invented certain new and ruseful Improvements in Fan Belts, of which the following is a specification.

My invention relates to an improvement in fan belts, particularly that type known as a V belt'.

Belts of this type have been made of rubberized fabric, either cord or square woven, or a combination of both. SuchA belts howeverhare the fabric substantially uniformly distributed throughout their cross section' vand for that reason .are subject to unda sirable strainswhen the belt turns around the pulley and exposure of the fabric.

1t is the object of my invention to provide a construction which will absorb the working strains without damage to the fabric.

lnfthe accompanying 'drawing showing Y one embodiment of my invention-u F'igure l. represents a fragment of a belt in perspective.

.Figure 2 is a similar view ofl a modification. Y

. In the drawings 1 represents the core of the belt, preferably.composed of bias cut rubberized cord fabric, rolled upon itself, and 2 shows-a covering.; of square woven bias eut rubberized fabric rolled about the core. At 3 is shown an outer covering of4 rubber which is rolled about the fabric covering; The so formed belt is molded to a.l cross section, shown in Figure l, providing `a fiat base and diver-ging sideswhile the Atop is formed with curvin depressions 5 meeting the sides of the be tto form rela.-y

tiyely sharp thin laterally rojeeting ears or wings 4, and meeting at t 1e center to form a rounded stiii'ening rib 6. In the molding operation the rubber covering flows outwardly toward the edges so that the ears -i and rib (i in the completed .beltare `formed ot' rubber and readily yield when the outer periphery of the beit is subjected to tensile strain 1n rounding the pulley without exf posing the fabric covering the core, which "latter thereforel absorbs its share of such strain without deterioration and with a4 graduated transition from the excessive yielding ofthe ears 4.

The depressions 5 permit the outer periphery of` the belt to yield transversely if necessary to accon'm'iodate variations inthe size ot -the `uilley groove and rib 6 is-provided to stii'en the periphery against excessive 'transverse strain and to absorber transfer the tensile strains at the center of the outer periphery.

.Figure shows a slightly modified form of my -V belt'in which the base is rounded,

. the structure otherwise being the same.

Having described the preferred form of my improved belt I claim as my invention:

An endless V type belt comprising a core of cord fabric, a. square Woven fabric covering about said core', an, outer covering of relatively 4,soft rubber, the outer` periphery of said belt being provided with longitudinal curved depressionsforming tapering yielding ears at the outer peripheral edges, and a rounded reinforcing rib between said ears.

In testimony whereof I have signed my name to the a BENJAMINITL PRATT.-

ve speci fication. 

